Inner Grooved Aluminum Tube

1. Production Name: Inner Grooved Aluminum Tube
2. For: This specification applies to the supply all customers
3. Quality requirements
3.1 General requirements
3.1. 1 The inside and outside surface of tube are clean and bright.
The inside and outside surface of tube should be no pitting, impurities, die tracks and cracks. The inside of tube must be cleaning and without chips and moisture.
3.1. 2When the whole tube goes through Eddy-current Detector, the printed black marks which are 500mm length in the bug position.
3.1. 3The number of the defects shall be below 10 for each coil.
3.1. 4 Impurities ≤ 38mg/m2.

3.2 Chemical Composition
The chemical composition of tube should be consistent with table -1

Table-1 Chemical Composition for AA3003
Chemical Composition(wt%)(≤ )
Alloy Si Fe Cu Mn Zn Ti others Al
Single total
AA3003 0.6 0.7 0.05-0.20 1.0-1.5 0.1 -- 0.05 0.15 Residue

3.3 Mechanical Property of tube
Mechanical Property of tube should be consistent with table-2
Table-2 Mechanical Property for AA3003-O tube
Temper Tensile Strength (N/mm2) Elongation
O > 95 > 25
Expanding: 60° Expanding, without cracks under 20% expanding.

3.4 Tube Specification and tolerance
Tube specification and Tolerance should be consistent with table -3

Table-3 Tube Specification and tolerance
Item Symbol Specified size Tolerance
Φ 7*0.5*0.15 Average Tolerance
Out diameter OD(mm) 7.10 7.10 ± 0.12
Bottom wall thickness T1(mm) 0.50 0.5 ± 0.08
Groove Height H1(mm) 0.15 0.15 ± 0.05
Helix angle β (° ) 18 18 /
Addendum angle α (° ) 45 45 /
Number of Grooves N 40 --- ± 0
Unit weight G(G/M) 34.5 --- ± 2
Coil weight Kg 50~120

4 Testing items &Frequency
Tube testing items &Frequency should be consistent with Table-4
Table-4 Testing items &Frequency

Item Method of inspection Sample numbers
Chemical composition Spectrophotometric method 1time/lot.
Eddy-current detector JL. QH-ZY-14 Full number
Mechanical Properties GB/T228-2002 2times/batch
Other dimensions JL. QH-ZY-27
JL. QH-ZY-20 2times/coil
Expansion test GB/T 242_2007 1time/batch

5 Certificate of Quality
5.1 The specific content of the quality certificate please check the "Inspection/Test Certificate" sample document.
6 Packing &Transportation
6.1 The schematic of packing is shown as below:
6.1. 1 The products are packed by winding films with 2~4 coils together.
6.1. 2 The packing of each stock is from bottom to the top and the orders are: 750~1100 round wooden stock, plastic bag, solid paper washer, several pans of Al tubes with hollow paper washer between each two pans, hollow paper washer, wooden tray, 1400*1400mm plastic face cloth, slab.
6.1. 3 The stock is thoroughly winded by the films twice, then the slab and wooden stock are nailed together. After that, the stock is winded by winding film for three times in the lower part and two times in the upper part.
6.2 Each batch of product has certificate of quality.
6.3 The products should be stocked under dry and draughty environment and avoided of direct sunlight, rain and acid or alkali atmosphere.
6.4 There is a label on each package with the following information:
(1) Material &Temper
(2)Specification size
(3)Batch No.
(4)Production Date
(5) Coil quantity and coil weight
(6) Manufacturer name
(7) Defect per coil
7 Others
7.1 Agreeing to change the supplied products unconditionally if they can not meet with the requirements on the specifications within one year after delivery of the products.
7.2 The product certificate will be prolonged naturally if two parties have no objection.
7.3 In case of revision and abolition for the specification, two parties shall discuss the issue and decide it.